• Stormwater is contaminated by accumulated wastes.storm sewer structure image by jimcox40 from Fotolia.com
  
  Thousands of types of bacteria can be found in stormwater, but the most virulent types are associated with stormwater contaminated with fecal matter. Animal waste accumulates during periods without rain, and rain can dissolve the excrement and release bacteria into stormwater. Stormwater can also be contaminated with human waste through sewage overflows.
  
  

Coliform Bacteria in Stormwater

• Animal waste contributes a lot of bacteria to stormwater.scoop the poop image by Joyce Wilkes from Fotolia.com
  
  Coliform bacteria exist in the intestines of warm-blooded animals. This is a group of bacteria consisting of hundreds of species including Escherichia coli, found in humans as well as animals. Certain types of E. coli can be pathogenic; other types are used as indicators of how badly stormwater is polluted. The strain 0157:H7 is known to come from farms with lambs, goats, pigs and rabbits. It is also found in deer and human waste. Fecal coliforms from humans can reach stormwater from leachate, intentional sewage discharges and runoff from pastures. It is also found in runoff from virtually any paved surface, where it can be deposited in animal droppings, or can accumulate through airborne dust.
  
  

Pathogenic Bacteria

• Salmonella can sometimes be found in reptiles.lizard image by pearlguy from Fotolia.com
  
  Salmonella causes several diseases including typhoid fever. Salmonella can come from contaminated food or the excrement of pet reptiles, but is not always found in stormwater. Campylobacteria cause gastroenteritis in humans. Campylobacteria are found in bird, livestock and human guts. It is able to survive in salt water and presents a hazard when it infects food sources like shellfish. Pseudomonas bacteria may be the cause of swimmer's ear, and is one of the most abundant bacteria in urban stormwater runoff.
  
  

Streptococci and Staphylococci

• Urban stormwater can affect the health of surfers and swimmers.surfer image by bacalao from Fotolia.com
  
  Many animals and most humans have enterococci bacteria in their intestines, where they are not usually harmful. However, if they are exposed to skin, cuts or mucous membranes, enterococci like streptococcus can cause infection. Streptococcus infections are difficult to treat, even with antibiotics. Staphylococcus bacteria can cause skin lesions such as boils, abscesses and impetigo. This is a common malaise of swimmers and surfers near urban runoff areas.